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(No Model.) 3- Sheets-Shet 1. E. T. HERRIGK.

AUTOMATIC GLUTGH FOB, ELEVATORS. No. 274,770. Patented Mar. 27,1883.

I if I! O INVENTORI Edwin TJiErr ick.

3 Sheets- 811961; 2.

(No Model.)

B. T. HERRIGK. AUTOMATIU CLUTCH FOR ELEVATORS.

Patented Mar.Z7,1883.

A Fig.2. Fig.5.

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WITNESSESI, INVENTORI- Edwin ZHerricin; I

3 Sheets-Sheet 3.

E. T. HERRIGK. AUTOMATIC CLUTCH FOR ELEVATORS.

(No Model.)

Patented Mar.27,1883.

,INVEN T-ORL E0171! i7! [Ferric-7g W TNEssEsL u PETERS. mouuw n v r.Wuhinllam o c.

UNITED STATES PATENT OFFICE.

EDWINT. HERRIOK, or PROVIDENCE, nnonn ISLAND.

AUTOMATIC CLUTCH FOR ELEVATORS.

SPECIFICATION formingpart of Letters Patent No. 274,770, dated March 27,1883.

Application filed August 18, 1881. Renewed October 14, 1882. (No model.)

ment in automatic safety-clutches forall kinds of elevators or hoists.

The object of my invention is sot'o arrange an automatic safety-clutchthat as soon as from any cause the platform of the hoist or elevatorshall commence to descend quicker than desired, and before any momentumis acquired, the safety-clutch will be automatically engaged and thedescent arrested.

The invention consists in the peculiar construction of the double rackand the safety pawls, as will be more fully set forth hereinafter, andpointed out in the claims.

Figure 1 is a perspective view of part of a hoist or elevator platformprovided with my improved safety-clutches. Fig. 2 is a sectional view ofpart of the hoist or elevator platform, showing the safety-clutchsecured thereto, the double rack secured in the elevator-well, and thecovered guide-rail. The pawl is connected with the platform by a link,so that the clutch can accommodate itself to the variations in thedistance between the racks. 'Fig. 3 is a sectional view of part of theplatform of a hoist or elevator, the double rack, the curved guide-rail,and the safety-clutch. Fig. 4. is a top view of the bracket in whichthe.safetyclutch is hinged, showing the rack in section. Fig. 5 is aview, partlyin section, showing the cushioned bearing by which the pawlor safetyclntch is connected with the platform of a hoist or elevator,so as to, break the blow caused by the sudden arrest of the descendinghoist. Fig. 6 is a view of the safety-clutch, shown in solid lines asguided by the curved rail on the concave portion of the rail and inbroken lines as engaged with the inner shoulder of the rack. Fig.'7 is aview of the safety clutch in solid lines, showing the rider-wheel incontact with the convex portion of the guide-rail, and in brokenlinesthe pawl as entered in the rail, as would be case if the elevator hadsuddenly descended at the point shown in solid lines.

. In the drawings, A is the peculiarly-formed rack. B is the pawl; O,the rider-roll; D, the curved guide-rail, and E the bracket in which thepawl is hinged.

It will be observed that the guide-rail and the rack are made so as toconform to each other-that is to say,one of the shoulders of the rack isat the outward curve of the guiderail and one at the inward curve. Theobject of this arrangement is to prevent any considerable descent of thehoist or platform before the same is arrested, and thereby prevent thepossibility of the hoist or platform acquiring any momentum.

On examining Fig.6it will be observed that if an elevator provided withmy improved safety-clutch were to descend suddenly the rider-wheel G,which is in the concave portion of the guide-rail, would roll toward theconvex curve and enter the pawl in the rack at a, as is shown in brokenlines, and if the position of the rider-wheel O is at the convex curve,

as shown in solid lines in Fig. 7, the pawl B is already in the positionto encounter. the

shoulder of the rack at b. By this peculiar construction of the rack, inconnection with the guide-rail, the moment the descent is suddenlyaccelerated the hoist or platform is instantly arrested, and in thispeculiar construction consists the main and most important value of thisinvention, and the broad and. essential difference between it and allsafetyclutches for hoists or elevators previously constructed. It isevident that the racks'may be placed so that all the pawls enter thecorresponding rack at the same time; or one set of racks may be arrangedintermediate, so as to still more reduce the distance that the hoist orplatform can fall before it is arrested.

E is a weight by which the rider-wheel is kept in contact with theguide-rail, so as to allow the pawl to oscillate in close proximity withthe rackwhen the hoist or elevator ascends or descends in the ordinaryway.

F is the bracket shown in top View in Fig.

-on the sides of the rack A, and therefore follows the rack. As,however, there is of necessity some play to the hoist or cage, and as itis difficult to secure the rack at all places perfectly straight, thecage or hoist can be connected with the bracket F by means of a link, asis shown in Fig. 2, in which G forms the connecting-link; or it may beconnected in any other suitable manner to allow free play of the cage orhoist.

In Figs. 2 and 3,H is the hoist or cage platform. To this platform, orany part of the cage or hoist above the cage, on the sides or below thesame, the box I is secured, and in the box I the bearing-block K isplaced and constructed so as to have a certain amount of vertical play,and the coiled springs L L or some elastic cushion is placed between thebearing-block K and the box I, so as to gradually arrest the descent ofthe cage or hoist when the pawl or pawls B B enter the rack.

"The bearing-block K is connected with the bracket F either directly, asis shown in Fig.

3, or by a flexible connection, as is shown in Fig. 2. To adjust thepawls with the greatest possible nicety, so as to oscillate as close aspossible to the rack without engaging with the same until the hoist orelevator descends suddenly, the rider-wheel O is placed on a separatearm, M, which is hinged to the pawl B or to the weight E, and providedwith an adjusting-screw, N, at its lower end, as is 'shown in Fig. 3.

By the use of this automatic safety-clutch an elevator may ascend ordescend with great speed and in perfect safety as long as the descent isof uniform or nearly uniform velocity. As soon,however, as the descentisaccelerated by the giving way of the supporting-rope or other devices,the automatic safety-clutch will engage with the rack or racks andinstantly arrest the descent, thus converting any hoist 'or elevatorinto as safe a means for ascending or descending as a stair.

This peculiar automatic safety-clutch is peculiarly well adapted. forinclined railroads, and, if properly constructed, it may be connectedwith each car by a link, so as to allow perfect freedom to the cars inthe ascent or descent, as well as the action of the springs on the cars.The rackand guide-rail may be placed between the other rails, and shouldbe constructed in a substantial manner, so as to insure perfect safety.

Having thus described my invention, I claim as new and desire to secureby Letters Patent- 1. The combination, substantially as before setforth, of the hoist, the sliding bracket suspended therefrom .by a link,the rack, the serpentine guide-rail, and the pawl hinged to the bracketandconnected with a rider moving on said guide-rail.

2. The combination, substantially as before set forth, of the hoist, themovable-bearingblock thereof, the springs, the sliding bracket suspendedfrom the movable bearing-block by a link, the rack, the serpentineguide-ra1l,aod the pawl hinged to the bracket and connected With a ridermoving on said guide-rail.

3. The combination of a hoist with the box I, the bearing-block K,connected with the bracket F, having the safety-clutch hinged thereto,constructed to have vertical p1ay,and the coiled springs L L, interposedbetween the block K and the box I, as and for the purpose set forth. Y

4. The combination, with the rack A and curved guide D, of the hingedpawlB, having the rider-wheel O, secured to the hinged arin M, providedwith the adj ustiug-screw N, constructed to adjust the safety-clutch soas to allow the pawl to oscillate in close proximity to the rack, asdescribed.

EDWIN T. HERRIOK.

Witnesses:

HENRY J. MILLER, WM. L. 000K.

